Air-pump.



L. B. SHERWOOD.

AIR PUMP. APPLICATION FILED MAY 27, 1910.

Patented Oct. 21, 1913.

[ V/TNESSES: JNI EIVTOR.

. 4 I 5/44 M @MM 6 Z ,X ZQ BY fifl LINCOLN B. SHERWOOD, F INDIANAPOLIS, INDIANA.

AER-PUMP.

, Specification of Letters Patent.

- Patented Oct. 21, 119.113.

Application filed may 27, 1910. Serial No. 568MB.

To all whom it may concern:

Be it known that I, Lmoonn B. Srinawooo, citizen of the United States, resid ng at Indianapolis, in the county of Marion and Si ate of Indiana, have invented certain new and useful Improvements in Air- Pumps, of which the following is a specification.

My invention relates to improvements in air pumps and has for its objects the protection of the valves and packings in the piston, which are preferably'of leather and well oiled to give best service and such as are placed within the oil tank and below level of the liquid therein, and where air pressure is to be pumped into the tank above the liquid, that the said liquid may be forced to a higher level or under pressure to the generator in a soldering furnace, having meansiprovided to shield check valve entirely from the liquid in which the pump may be submerged,

My device is more especially useful in the equipment of a popular soldering furnace, with which I have had a greatdeal to do, and in which gasolene has always caused the rapid deterioration of the valves and piston packingsfwith means for shielding the packings and valves in the plunger absolutely from contact with or deterioration caused by the act-ion of gasolene, and I attain these objects by such means as shown in the accompanying drawings and described in the following specification and more particularly pointed out in the claim.-

In the diifcrent figures of the drawings and throughout the specification, like numerals are employed to point out or refer to like parts and Figure l is a side elevation of a gasolene tank in use on a common type of soldering furnace, detached with pump in position; Fig. 2 is a broken side elevation part sectional view of same detached; Fig. 3 is an enlarged partial broken side view of said tank showing pump partly in section and in position; Fig. 4 is a detached broken vertical section of the pump and shield.

Numeral 1 in the difierent figures repre* sents the tank; 2 the cap of the filler opening; 3 the pipe conducting fuel oil to the burner; 4 shows the depending end of the fuel pipe adapted to conduct all the oil from t the tank; 5 is an internally threaded bushing or fitting soldered in upper side of tank and adapted to receive the pump and shield;

further lag an 6 is the pump cylinder; 7 is the shield surrounding the pump and is of larger diameter than said cylinder providing an annular air space 8 around the pump cylinder and is provided at or near the upper end thereof and at a point within the tank with an air out let opening 9 communicating directly with the compressed air space 20; 10 is a contracted tubular nipple, the discharge opening from the pump emptying the compressed air from the pump into' the air space around the pump and through the port?) into the. compressed air space over the oil within the tank; the said nipple '10 terminates in a con tracted surface and is closed bya block of cork or other suitable yielding material 11 which is spring pressed by light springs 12, constituting the check valve,

13 is a knob or handle end of pump piston by which the pump is manipulated.

14 is a screw threaded fitting secured to the pump cylinder near its upper end and is provided at 15 with a thread adapted to screw into the fitting 5, and the threaded sectio is reduced in diameter to the extent of few threads at '16 but retaining the same pitch throughout and is adapted to be screwed into the internally screw-threaded end of the shield 7 which is provided also at 17 with an externally threaded section of same pitch and equal diameter of thread 15 on part 14 to the extent of two or three threads, whereby the shield may be assembled with the pump and the pump and shield so combined, whereafter they may together be screwed into the tank.

The llSGsOf a tank and pump constructed as I have otherwise shown, but without the protecting shield, has been for several years introduced and used quite extensively and in almost all cases where the apparatus has been much used, leaks have developed at the check valve 11, and gasolene was forced from the tank into the pump by static air pressure and the lubricating oil in the leather piston packings was soon dissolved and carried off by the gasolene and the. packings would soon become hardened, ineffective and useless and would often have to be renewed, ca gsing delays and expense thathave been practically if not entirely' elin'ii'nated by the application of the protect ing shield; another and the worst phase of the rif le of un often cause ,"the pump used as applied without a shield such as 1 desirable results possible and ion ' pumped up in the tank and any small solid ounces oily substance should lodge between the tip of nipple l0 and the check valve, or a sufiicient leak from any cause SllOllldO C Clllftll pump may soon be filled to overflowing as a few would be required to fill the pump cylinder when the gasolene would overflow spreading over the tank, and there is then imminent danger of fire from this source, 7

It is evident that several deviations and alterations might be resorted to without departing from the "spirit and scope of my invention to'attain like results and I would have it understood that I hold myself at liberty to employ any such alterations and deviations as fall fairly within the spirit and scope of my invention, and 4 What I claim as new and desire to secure by Letters Patent is,

An air pump, a externally screw threadved collar securedii'ear upper end of pump cylinder, a screw-threaded section on said collar of two diameters but of equal pitch throughout? the larger diameter joining radial flange of collar, a closed end shield of light metal surrounding said pump, an eiternally and internally threaded section at open end of said shield, the internally threaded section ,thereof matching the smaller threaded section on said collar, and the outer threaded section equaling the diameter and meeting the pitch of the larger threaded section on said collar that when the shield is assembled with the pump the external section of thread and shield present a continuous thread of even diameter and pitch and a tank provided with an internally threaded opening adapted to receiv assembled. 1

In testimony whereof I afiix my signature in presence of two witnesses.

LINCOLN B. SHERWOOD. Witnesses: E; D. T. BROWN, C. S. TEETGR.

on said collar.

the pump and shield s0 

